Pete Wentz filed legal papers today asking for joint custody of Bronx, which appears to be a response to ex-wife Ashlee Simpson filing for sole custody of their son last month.

Wentz also requested that each party pay their respective legal fees (Simpson asked that Wentz pay for the both of them), and though experts say there isn't enough detail in the divorce filings to predict a bitter custody battle, Pete is clearly unhappy with Ashlee's requests.

Just days after their divorce announcement, Simpson and Wentz released the following statement: "We remain friends and deeply committed and loving parents to our son Bronx, whose happiness and well-being remains our number one priority."

Click the gallery below to see Pete and Bronx out and about in LA yesterday afternoon.

Seems like Pete's been stepping out with Bronx quite a bit more lately...coincidence?